Not Applicable
The present invention is directed to a food patty molding machine and in particular to improvements in the operating structure of a known food patty molding machine such as described in FIGS. 1 through 8B.
A FORMAX-12 brand food patty molding or forming machine 30 manufactured by Formax, Inc., of Mokena, Ill., U.S.A. is shown in FIGS. 1-8B. The operation of the machine is generally described in U.S. Pat. Nos. 4,182,003; 4,054,967; and 3,952,478, herein incorporated by reference.
This machine includes a sheet metal housing 34 which encloses the mechanical equipment of the machine. The housing is supported on wheels 35a and/or leveling legs 35b. A hopper 36 is situated at an elevated position on the machine. The hopper includes an open top 40 for receiving bulk food products, for example, whole muscle chicken or ground beef. A pair of feed screws within the hopper (not shown) drives the food product into a pump box area 44 where a reciprocating pump 45 (FIG. 2) presses the food product into mold cavities 46 (shown in FIG. 9) of a reciprocating mold plate 47. The mold plate is reciprocated out of the pump box area to a knock-out area 50 where knock-out cups 52 push the formed meat product or patties out of the cavities and onto a conveyer 56 (FIG. 2). A paper placing station 58 includes mechanisms to interleave paper between patties during the dropping of the patties onto the conveyor.
FIG. 2 illustrates the machine of FIG. 1 with an access door 57 open. The knock-out cups 52 are held on a horizontal bar 60 which is supported by two spaced apart knock-out bar arms 64. The knock-out bar arms 64 are clamped to two vertical, reciprocating knock-out rods 70. The rods 70 are journaled or supported at positions 71a on a mold cover 71 below the knock-out bar arms 64. Because the rods 70 can have a substantial unsupported or unguided length above the position 71a, high bending stress can be realized in the rod 70.
As shown more clearly in FIG. 6, the rods 70 are driven by the rotation of cams 72 which are mounted on a cam shaft 73 rotationally mounted to the machine frame. The cam shaft 73 is driven to rotate by a sprocket 74. The sprocket is driven by a drive chain 75, which is driven by the power train of the machine.
The cams 72 have cut-out, flat regions 78. Knock-out arms 79 are pivotally connected to the machine frame at a bolt or axle or pivoting connection 79a and have arcuate ends 80 which slide along the rotating cam surface 84. When the ends 80 reach the cut out, flat regions 78 of the cams, the knock-out arms 79 rotate downwardly in the direction R, and then rotate upwardly in a reverse direction when the flat regions 78 have passed. Thus, rotation of the cams 84 causes an up and down pivoting of the knock-out arms 79 about the connection 79a. An opposite end 90 of each of the knock-out arms is connected to one knock-out rod 70 by a bolted linkage 92 and by a bolt 94. Extending outwardly from each rod 70 is a flag or lug 96 having a hole for receiving a machine screw 98 which is threaded into one of two opposite ends of a spacer rod or tie rod 100. The flag 96 is possibly subjected to high bending or twisting forces during operation and can possibly be subject to cracking due to fatigue.
An oil pan 101 is located beneath each cam 72. One will be described, the respective other is mirror image identical. A front wick 102 made of a woven, sponge or other wick material, is located at the pivoting connection 79a, held in place by a washer 102a to continuously oil the pivoting connection 79a. A rear wick 103 is held against the cam surface 84 to continuously oil the interface between the region 78 and the end 80 of the knock-out arm 79. The pan has an open top 104 into which the wicks 102, 103 are dipped. The pan 101 holds a supply of oil 105. It can possibly be a maintenance problem that sprayed wash water inadvertently enters the open top 104 of the pan 101 and contaminates or otherwise washes out the oil.
Each bolted linkage 92 is also connected by a bolt 95a to a vertical leg 95b of a movable plate 95. The plate is held within a guide frame 97 which is mounted by machine screws to a stationary part of the machine frame, at a top of the frame 97. Two springs 95d are mounted between an upper wall of the frame and a bottom leg 95c of the plate and resist the upward lifting of the plate within the frame. The springs are therefore the driving downward force generator of the knock-out operation. In FIG. 4D the springs are shown compressed with the knock-out rod lifted by the associated cam 72. In FIG. 6, the springs are expanded, and the knock-out rods have been driven to their downward position.
The knock-out bar arms 64 are mounted to top ends of the rods 70. The bar arms 64 are each fixed vertically to a rod by a top fastener 64a and rotationally by a clamp arrangement 64b closed by a horizontal fastener 64c. The bar arms 64 are fastened by bolts or machine screws to the horizontal bar 60 which holds the knock-out cups 52. Depending on the product being formed the bar 60 and cups 52 can have a different shape, and/or the bar can carry different number of cups.
Also shown in FIG. 2 is a vacuum bar assembly 106 which reciprocates during operation of the machine as part of a vacuum transfer shuttle or vacuum bar assembly for interleaving flexible paper sheets with formed patties as described in U.S. Pat. Nos. 3,952,478; 4,182,003; or 4,054,967. Also included is a paper placer assembly 107 which places the flexible paper sheets onto the vacuum bar assembly. Both the vacuum bar assembly and the paper placer assembly are driven by reciprocal motion of rods, i.e., by vacuum bar rods 108, 108a (see FIG. 8B) having a square cross section, and by a paper placer drive rod 110 having a round cross section, respectively.
FIG. 3 illustrates the reciprocating mold plate 47 connected via a hinge assembly 120 to a drive plate or slide plate 124. The drive plate 124 has an elongate rectangular cross section. The drive plate 124, the vacuum bar drive rod 108 and the paper placer drive rod 110 must all penetrate through, and reciprocate through the penetration of, a front wall or skin 130 which separates the food forming front section of the machine from the mechanical compartment. For sanitary reasons, at each penetration a sealing element is provided. The drive plate 124 requires a rectangular sealing element 140 bolted to the skin 130. A similar rectangular seal 144 must be provided at the vacuum rod drive bar 108 as it penetrates the skin 130. A circular seal 145 can be used at the paper placer drive rod 110 where it penetrates the skin 130.
FIG. 4A shows the vacuum bar drive rod or shuttle arm 108 penetrating the skin or wall 130. The rod 108 is connected via an intermediate plate 150 to a rack 152. The rack 152 is driven to reciprocate by a pinion 154.
FIGS. 8A and 8B show the arrangement of the vacuum bar drive rod 108 in more detail. The rack 152 is slidably held in a channel 153. It is to be noted that there are two drive rods 108, 108a arranged on a right side and a left side of the machine respectively. Each of the rods 108, 108a is connected to a rack and driven by a pinion 154 as shown in FIG. 8A. Each of the rods 108, 108a is connected to one lateral side of the vacuum bar 106 by two machine screws or bolts 156. The rods 108 pass through bearing blocks 160, 160a respectively before being connected to the vacuum bar 106. A paper placer drive sprocket 160 rotates a paper placer drive shaft 162 which rotates a paper placer crank arm 163 (shown in FIG. 4C) which drives the paper placer drive rod (via linkages) to reciprocate. The crank arm rotates about a horizontal axis of the drive shaft.
Returning to FIGS. 4A and 4B, the main drive motor 170 is shown driving a drive motor pulley 172 which drives a drive belt 174. The drive belt 174 drives a reducer pulley 176 which inputs rotational power to a mold plate drive reducer 180 (see FIG. 5). A reducer output shaft 182 outputs rotational power from the reducer 180. Sprockets and pulleys which are fixed to the output shaft 182 drive various systems including the drive chain 75 for actuating the knock-out rods 70, and a drive chain 185 for the paper placer sprocket 160. A hydraulic oil tank 186 is located at a front bottom portion of the machine. A rear output shaft of the main drive motor 170 drives a hydraulic pump 187 which powers the hydraulic systems of the machine. Also shown in FIG. 4B is a bottom skin or floor 188 which is located at an elevation equal to a bottom 190 of a bottom horizontal frame member 192. The bottom skin 188 substantially covers a bottom of the machine.
FIG. 5 illustrates that the drive system for the mold plate includes a long rocker arm 200 which is connected by a slide plate linkage 202 to the slide plate or drive plate 124. Laterally arranged slide bearings 206a, 206b receive lateral edges of the slide plate 124 and guide the reciprocating movement of the slide plate 124 therein. The lateral bearings 206a, 206b are fixed to the machine overhead structure. Also shown is a feed screw gear box 210 for driving the feed screws within the hopper 40. A cabinet blower 211 driven by a motor 212 is used to circulate cooling air or purge air through the housing 34.
FIG. 7 shows the drive for the molding plate 47 in more detail. The hinge assembly 120 includes fixed hinge plates 214a, 214b holding a hinge axle 216 upon which are mounted hinged grippers 218a, 218b. The axle 216 allows a degree of pivoting between the fixed hinge plates 214a, 214b and the grippers 218a, 218b respectively. The hinged grippers 218a, 218b include bottom jaws 219a, 219b which are fixed to the upper jaws by machine screws 220, but when the bottom jaws 219a, 219b are released by unscrewing of the machine screws 220, they can pivot downwardly about the axle 216 to allow downward removal of the mold plate 47. The mold plate 47 is provided with holes for allowing passage of the machine screws 220. The hinge plates 214a, 214b are fixed to the slide plate 124 by machine screws 224 which pass through the slide plate 124 and are received into threaded holes in an underlying part of the hinge plates 214a, 214b respectively.
The slide plate linkage 202 includes an adjustable female rod end 230 connected to a clevis 232 which is fixed to the slide plate 124 via a machine screw 236 which is threaded into an underlying part of the U-shaped clevis. The slide plate 124 includes a hole for receiving the machine screw 236. A bolt 238 connects the clevis 232 with an eye-bolt of the female rod end 230. This allows pivoting about the horizontal between the clevis 232 and the female rod end 230. A male rod end 240 is threaded into the female rod end 230 and includes an eye-bolt end 242 for receiving a bolt 246 to allow relative pivoting about the horizontal axis between the male rod end 240 and the long rocker arm 200. A short rocker arm 256 is fixed to the long rocker arm 200 by a shear pin 250 via a shaft 254. The short rocker arm 256 includes an adjustable follower 260 which rides in a shaped cam channel 266 formed in the mold plate drive cam 270. The mold plate drive cam 270 is driven in rotation by the mold plate drive reducer 180 (shown in FIG. 5). The interaction between the short rocker arm, the cam 270 and the long rocker arm causes back and forth reciprocation of the slide plate 124, and thus the mold plate 47.
The inventors have recognized that it would be advantageous to provide an improved patty forming machine, which reduces bending or twisting forces on the knock-out rods and which prevents to a great extent the contamination or washout of oil from reservoirs which serve for the lubrication of the knock-out cams and knock-out arm pivot connections to the machine frame.
The invention provides an improved patty forming machine. Particularly, the invention includes an improved knock-out apparatus for pushing formed food products or patties from mold plates. The apparatus includes improved knock-out rods having improved upper knock-out rod supports which reduce bending stress on the knock-out rods. The upper knock-out rod supports are inverted L-shaped supports each having a sleeve bearing in an overhang portion to guide a top extension of a knock-out rod inserted therein. The knock-out bar arm is located below the sleeve bearing.
The apparatus includes an improved spacer rod or tie rod attachment structure connected to the two knock-out rods to reduce fatigue failure at the connection location. The improved structure includes a pair of clamp blocks each of which clamps one of the knock-out rods around its circumference. The clamp blocks are fastened together by a spacer rod. The use of a unitary flag or lug used in the prior art knock-out rod is avoided.
The apparatus also includes an improved oiling system for the knock-out cam and pivot connection bearing surfaces. The oiling system includes two substantially enclosed reservoirs each having openings for receiving a wick for each of the cam surface and the pivot connection of the knock-out arm located at each side of the machine, respectively.
Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, and from the accompanying drawings in which details of the invention are fully and completely disclosed as part of this specification.